Hi Frank - I have to agree with Lowell - He did put it rather in a nutshell.

I have been attending a climate conference for the past 4 years so you could say I've heard the latest leading-edge research on the subject of climate.

Most researchers agree that we are warming - no one is hiding that - in 1976 we did have a couple year cooling but then it headed right back up - In the middle ages we also experienced a 'little ice age'.

Our planet is in a natural process of coming out of the last ice age - sea levels in the past have been 400 feet higher than they are today. The cycle of melting polar ice caps is nothing new on this planet.

The big multi-million dollar question is: Are humans adding to this process with our burning of fossil fuels?

There has been an increase in CO2 in the atmosphere which is one of the key greenhouse gases but overall the percent of atmosphereic CO2 is very small (280 ppm in the preindustrial era to about 364 ppm in 1997). There are many forces which add to the greenhouse gases such as volcanos, pockets of trapped methane that may release due to warming. Solar irradiance fluctuations also affect our climate and warming (some believe it is responsible for as much as half the observed surface warming since 1900). Water vapor is one of the most abundant greenhouse gases!

We aren't even sure how CO2 is taken up in our environment - or the other gases. I guess the bottom line is we really don't know enough - is it a natural cycle or not? The mathmatical models seem to contradict themselves as well.

There's a good article at the site listed below for 'just the facts' - Climate is truly a tough nut to crack.

Canie

• Climate Change and Greenhouse Gases